Ejemplo n.º 1
0
SimpleTemplate::SimpleTemplate(boost::string_ref text)
{
    static char const rawMarker[] = "@@";
    static boost::string_ref const marker(rawMarker, sizeof(rawMarker) - 1);

    auto beg = text.find(marker);
    while (beg != boost::string_ref::npos) {
        m_literals.emplace_back(text.data(), beg);
        text.remove_prefix(beg + marker.size());
        auto end = text.find(marker);
        if (end == boost::string_ref::npos) {
            std::string& lit = m_literals.back();
            lit.reserve(lit.size() + marker.size() + text.size());
            lit.append(marker.data(), marker.size());
            lit.append(text.data(), text.size());
            assert(m_literals.size() == m_insertionKeys.size() + 1);
            return;
        }
        m_insertionKeys.emplace_back(text.data(), end);
        text.remove_prefix(end + marker.size());
        beg = text.find(marker);
    }
    m_literals.emplace_back(text.data(), text.size());
    assert(m_literals.size() == m_insertionKeys.size() + 1);
}
double CInfixExpressionCalculator::ParseDouble(boost::string_ref &ref)
{
    SkipSpaces(ref);

    double value = 0;
    bool parsedAny = false;
    while (!ref.empty() && std::isdigit(ref[0]))
    {
        parsedAny = true;
        const int digit = ref[0] - '0';
        value = value * 10.0 + double(digit);
        ref.remove_prefix(1);
    }
    if (!parsedAny)
    {
        return std::numeric_limits<double>::quiet_NaN();
    }

    if (ref.empty() || (ref[0] != '.'))
    {
        return value;
    }
    ref.remove_prefix(1);
    double factor = 1.0;
    while (!ref.empty() && std::isdigit(ref[0]))
    {
        const int digit = ref[0] - '0';
        factor *= 0.1;
        value += factor * double(digit);
        ref.remove_prefix(1);
    }

    return value;
}
double CInfixExpressionCalculator::ParseExprSum(boost::string_ref &ref)
{
    double value = ParseExprMul(ref);
    while (true)
    {
        SkipSpaces(ref);

        if (!ref.empty() && ref[0] == '+')
        {
            ref.remove_prefix(1);
            value += ParseExprMul(ref);
        }
        else if (!ref.empty() && ref[0] == '-')
        {
            ref.remove_prefix(1);
            value -= ParseExprMul(ref);
        }
        else
        {
            break;
        }
    }

    return value;
}
void CInfixExpressionCalculator::SkipSpaces(boost::string_ref &ref)
{
    size_t i = 0;
    while (i < ref.size() && std::isspace(ref[i]))
        ++i;
    ref.remove_prefix(i);
}
Ejemplo n.º 5
0
  inline boost::string_ref remove_leading_spaces(boost::string_ref string, const char* spaces = " \t\r\n")
  {
    auto pos = string.find_first_not_of(spaces);
    if (pos == std::string::npos) pos = string.size();

    string.remove_prefix(pos);
    return string;
  }